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Pooled review (meta-analysis)

Pooled review of 24 studies, 1,768 adults: fasting did not clearly beat calorie cutting

Elortegui Pascual and colleagues · Obesity (Silver Spring, Md.) · 2023

Original title: A meta-analysis comparing the effectiveness of alternate day fasting, the 5:2 diet, and time-restricted eating for weight loss.

Under review. A person has not yet checked this summary against the paper. It is written from the PubMed abstract. Until a person checks it, search engines are asked not to list this page.

What the study found

No difference

Fasting plans gave similar weight loss to calorie cutting: mean difference 0.26 kg (95% CI: -0.31 to 0.84; p = 0.37). Alternate day fasting ranked highest, then calorie cutting, then time restricted eating.

The study at a glance

Type of study
Pooled review (meta-analysis)
Who or what was studied
24 studies, 1,768 people · adults in the general population
What was tested
alternate day fasting, 5:2 diet and time restricted eating, vs daily calorie cutting
What it measured
The question itself: weight loss, compared with ordinary calorie cutting
Who has a stake
Company stake
Funded by Nestle; several authors are Nestle employees.
Journal
Obesity (Silver Spring, Md.), 2023
Source
PubMed record 36349432. This page is based on the abstract only.

How much this study counts

  • ✓Pools the results of 24 studies with 1,768 people.
  • •A pooled review is only as strong as the studies it pools.
  • ✓Measured the question itself: weight loss, compared with ordinary calorie cutting.
  • –Company stake: Funded by Nestle; several authors are Nestle employees.
  • •Summarized from the PubMed abstract only. The full paper may hold details the abstract leaves out.

✓ Strength– Limit• Note

These points come from fixed rules about the type of study, its size and length, what it measured, and who has a stake. Every study on Digestery gets the same rules.

Where this study sits

This paper is not on the ladder. It is a pooled review (meta-analysis), and reviews and opinion pieces discuss studies that are already counted on the steps below.

↑ Stronger evidence

  1. Trials in people: weight loss

    9

    5 benefit, 2 mixed, 2 no difference

  2. Trials in people: other measures

    8

    4 benefit, 3 mixed, 1 no difference

  3. Trials in people: lab tests or safety

    1

    1 benefit

  4. Population studies

    0

    None among the papers we read.

  5. Blood levels and genes

    0

    None among the papers we read.

↓ Weaker evidence

  • Points to benefit
  • Mixed
  • No difference
  • No direction
  • Points to harm

How it fits with the other research

The short answer to “Does intermittent fasting help with weight loss?”

Yes, but about like calorie cutting.

Confidence: moderate. Based on 26 on-topic papers.

Read the full answer
  • Quoted in “What we found”: Against daily calorie cutting, fasting gave about the same weight loss in a 24-trial analysis of 1768 people: a gap of 0.26 kg that could be zero.
  • Part of the finding “Against daily calorie cutting, about the same”.
  • Summed up in “What reviews found”: Pooled 24 trials with 1768 people. Fasting plans gave about the same weight loss as daily calorie cutting (mean difference 0.26 kg). Alternate-day fasting ranked first. Nestlé funded the work.
  • Open item for a person: Pooled reviews Semnani-Azad 2025, Elortegui Pascual 2023, Zhang 2022 and Welton 2020 likely share many trials; their results are not independent.

Other reviews on this question

See all 26 studies on this question

How this page was made

Label

First read of the abstract
Claude Sonnet
Independent second read
Claude Haiku
Differences settled
The two reads agreed on every checked field. Claude Opus 5.5.
Headline
Claude Sonnet, from the checked study record. A script checked its numbers and wording.
Numbers
Checked against the abstract by a script
“How much this study counts”
Fixed rules, the same for every study
Source check by a person
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